Methods, systems, and devices to enhance fracturing fluid delivery to subsurface formations during high-pressure fracturing operations

ABSTRACT

Methods, systems, and devices to enhance fracturing fluid delivery to subsurface formations to enhance hydrocarbon production from the subsurface formations may include providing a manifold coupling having a manifold coupling passage with a manifold coupling axis. The manifold coupling may include a first inlet passage positioned to provide fluid flow between a first fracturing fluid output and the manifold coupling passage, and a second inlet passage positioned opposite the first inlet passage to provide fluid flow between a second fracturing fluid output and the manifold coupling passage. The first inlet passage may have a first inlet passage cross-section at least partially defining a first inlet axis extending transverse relative to the manifold coupling axis. The second inlet passage may have a second inlet passage cross-section at least partially defining a second inlet axis extending transverse relative to the manifold coupling axis and not being co-linear with the first inlet axis.

PRIORITY CLAIM

This is a continuation of U.S. Non-Provisional application Ser. No. 17/303,150, filed May 21, 2021, titled “METHODS, SYSTEMS, AND DEVICES TO ENHANCE FRACTURING FLUID DELIVERY TO SUBSURFACE FORMATIONS DURING HIGH-PRESSURE FRACTURING OPERATIONS,” which is a continuation of U.S. Non-Provisional application Ser. No. 17/303,146, filed May 21, 2021, titled “METHODS, SYSTEMS, AND DEVICES TO ENHANCE FRACTURING FLUID DELIVERY TO SUBSURFACE FORMATIONS DURING HIGH-PRESSURE FRACTURING OPERATIONS,” which claims priority to and the benefit of U.S. Provisional Application No. 63/201,721, filed May 11, 2021, titled “METHODS, SYSTEMS, AND DEVICES TO ENHANCE FRACTURING FLUID DELIVERY TO SUBSURFACE FORMATIONS DURING HIGH-PRESSURE FRACTURING OPERATIONS,” and U.S. Provisional Application No. 62/705,850, filed Jul. 17, 2020, titled “METHODS, SYSTEMS, AND DEVICES FOR ENERGY DISSIPATION AND PROPPANT SUSPENSION BY INDUCED VORTEX FLOW IN MONO-BORE MANIFOLDS,” the disclosures of which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to methods, systems, and devices to enhance fracturing fluid delivery to subsurface formations during high-pressure fracturing operations and, more particularly, to methods, systems, and devices to enhance fracturing fluid delivery via fluid manifold assemblies to subsurface formations during high-pressure fracturing operations, including enhancing dissipation of fluid energy associated with the fracturing fluid, enhancing suspension of proppants in the fracturing fluid, and/or enhancing fracturing fluid drainage from the manifold assembly.

BACKGROUND

Hydraulic fracturing is an oilfield operation that stimulates the production of hydrocarbons, such that the hydrocarbons may more easily or readily flow from a subsurface formation to a well. For example, a hydraulic fracturing system may be configured to fracture a formation by pumping a fracturing fluid into a well at high pressure and high flow rates. Some fracturing fluids may take the form of a slurry including water, proppants, and/or other additives, such as thickening agents and gels. The slurry may be forced via operation of one or more pumps into the formation at rates faster than can be accepted by the existing pores, fractures, faults, or other spaces within the formation. As a result, pressure builds rapidly to the point where the formation may fail and may begin to fracture. By continuing to pump the fracturing fluid into the formation, existing fractures in the formation may be caused to expand and extend in directions away from a wellbore, thereby creating additional flow paths for hydrocarbons to flow to the wellbore. The proppants may serve to prevent the expanded fractures from closing or may reduce the extent to which the expanded fractures contract when pumping of the fracturing fluid is ceased. Once the formation is fractured, large quantities of the injected fracturing fluid may be allowed to flow out of the well, and the production stream of hydrocarbons may be obtained from the formation.

To pump the fracturing fluid into the wellbore, a hydraulic fracturing system including prime movers may be used to supply power to hydraulic fracturing pumps for pumping the fracturing fluid into the formation through a high-pressure manifold configured to receive the fracturing fluid pumped to a high-pressure and flow rate by multiple fracturing pumps operating simultaneously. Each of the hydraulic fracturing pumps may include multiple cylinders and corresponding plungers that reciprocate in the respective cylinders to draw fracturing fluid into the cylinder through a one-way valve at low-pressure during an intake stroke, and force the fracturing fluid out of the cylinder through a one-way valve into the manifold at a high-pressure and flow rate during an output stroke. Each output stroke forces a charge of the fracturing fluid into the high-pressure manifold, which receives the collective high-pressure and high flow rate fracturing fluid from multiple fracturing pumps for passage to the wellbore. Rather than flowing in the high-pressure manifold at a constant pressure and flow rate, the fracturing fluid output by each of the output strokes of a plunger flows with a pulse of high-pressure and high flow rate upon each output stroke of each of the plungers of each of the fracturing pumps operating in the hydraulic fracturing system. This stroke sequence may result in large pressure oscillations in the high-pressure manifold.

This pressure oscillation is multiplied by the number of cylinders of the fracturing pump, which is further multiplied by the number of fracturing pumps operating during a fracturing operation. Some high-pressure manifolds, such as mono-bore manifolds, consolidate all of the fracturing fluid being pump by all of the fracturing pumps operating during a fracturing operation. Each of the fracturing pumps generates its own respective pressure pulsation waveform varying in amplitude and frequency from the pressure pulsation waveforms generated by operation of other fracturing pumps. While the volume of fracturing fluid in the high-pressure manifold and the geometry of the conduits between each of the fracturing pumps and the high-pressure manifold may result in dissipation of some of the energy associated with the collective pulsation waveforms, the energy associated with the pulsation waveforms may not be adequately reduced and may also introduce potential resonance in the form of standing waves inside the high-pressure manifold. This may result in inducing substantial vibration in the fracturing system, including the high-pressure manifold. Such vibration, if uncontrolled, may result in premature wear or failure of components of the fracturing system, including, for example, the high-pressure manifold, conduits between the fracturing pumps and the high-pressure manifold, manifold seals, the fracturing pumps, the prime movers, and transmissions between the prime movers and the fracturing pumps.

Moreover, a characteristic that may be relevant to the effectiveness of proppants in the fracturing fluid may be the level of proppant suspension in the fracturing fluid. For example, the manner in which the fracturing fluid flows through the manifold assembly may affect the homogeneity and/or consistency of the suspension of the proppants in the fracturing fluid pumped through the high-pressure manifold assembly, and some manifold assemblies may hinder the suspension of proppants in the manifold assembly.

In addition, because hydraulic fracturing systems are at least partially disassembled following a fracturing operation for transport to another site for use in another fracturing operation, the manifold assemblies are often drained, for example, for transportation to the next site or storage. Some manifold assemblies may be difficult to sufficiently drain, which may lead to additional weight during transportation as well as unbalanced loads. Further, fracturing fluids may contain corrosive materials and materials that may harden and adhere to the interior passages of manifold assembly components, which may result in premature wear or damage to the components, which may reduce the effectiveness of future fracturing operations.

Accordingly, Applicant has recognized a need for methods, systems, and devices that enhance fracturing fluid delivery to subsurface formations during high-pressure fracturing operations. For example, Applicant has recognized a need for methods, systems, and devices that enhance dissipation of fluid energy associated with the fracturing fluid, enhance suspension of proppants in the fracturing fluid, and/or enhance fracturing fluid drainage from the manifold assemblies. The present disclosure may address one or more of the above-referenced considerations, as well as other possible considerations.

SUMMARY

The present disclosure generally is directed to methods, systems, and devices to enhance fracturing fluid delivery via fluid manifold assemblies to subsurface formations during high-pressure fracturing operations, including enhancing dissipation of fluid energy associated with the fracturing fluid, enhancing suspension of proppants in the fracturing fluid, and/or enhancing fracturing fluid drainage from the manifold assembly. For example, in some embodiments, a manifold coupling may include first and second inlet passages for receiving respective outputs from hydraulic fracturing units and providing fluid flow between the outputs and a manifold passage of a manifold assembly. The first and second inlet passages may be oriented and/or configured such that fracturing fluid entering the manifold assembly via the first and second inlet passages promotes swirling of the fracturing fluid downstream of the manifold coupling and/or such that drainage of fracturing fluid from the manifold assembly is enhanced. Such swirling, in some embodiments, may enhance energy dissipation associated with the flow of the fracturing fluid, which may, in turn, dissipate and/or reduce vibration of the manifold assembly during a fracturing operation, and, in some embodiments, may enhance proppant suspension in the fracturing fluid flowing though the manifold assembly.

According some embodiments, a manifold assembly to enhance fracturing fluid delivery to a subsurface formation to enhance hydrocarbon production from the subsurface formation may include a manifold section including a manifold passage having a manifold cross-section and a manifold axis extending longitudinally along a length of the manifold section. The manifold axis may be substantially centrally located within the manifold cross-section. The manifold assembly further may include a manifold coupling connected to the manifold section. The manifold coupling may include a manifold coupling passage having a coupling passage cross-section defining one or more of a coupling passage shape or a coupling passage size substantially in common with one or more of a manifold passage shape or a manifold passage size of the manifold cross-section. The manifold coupling may further include a manifold coupling axis parallel to the manifold axis. The manifold coupling also may include a first inlet passage positioned to provide fluid flow between a first fracturing fluid output of a first hydraulic fracturing pump and the manifold passage. The first inlet passage may have a first inlet passage cross-section at least partially defining a first inlet axis extending transverse relative to the manifold axis. The manifold coupling further may include a second inlet passage positioned opposite the first inlet passage to provide fluid flow between a second fracturing fluid output of a second hydraulic fracturing pump and the manifold passage. The second inlet passage may have a second inlet passage cross-section at least partially defining a second inlet axis extending transverse relative to the manifold axis and not being co-linear with the first inlet axis.

According to some embodiments, a manifold coupling to enhance fracturing fluid delivery to a subsurface formation to enhance hydrocarbon production from the subsurface formation may include a manifold coupling passage having a coupling passage cross-section defining one or more of a coupling passage shape or a coupling passage size. The manifold coupling passage may include a manifold coupling axis. The manifold coupling further may include a first inlet passage positioned to provide fluid flow between a first fracturing fluid output of a first hydraulic fracturing pump and the manifold coupling passage. The first inlet passage may have a first inlet passage cross-section at least partially defining a first inlet axis extending transverse relative to the manifold coupling axis. The manifold coupling also may include a second inlet passage positioned opposite the first inlet passage to provide fluid flow between a second fracturing fluid output of a second hydraulic fracturing pump and the manifold coupling passage. The second inlet passage may have a second inlet passage cross-section at least partially defining a second inlet axis extending transverse relative to the manifold coupling axis and not being co-linear with the first inlet axis.

According to some embodiments, a hydraulic fracturing assembly may include a plurality of hydraulic fracturing pumps positioned to pump fracturing fluid into a subsurface formation to enhance hydrocarbon production from the subsurface formation. The hydraulic fracturing assembly further may include a manifold assembly positioned to supply fracturing fluid from two or more of the plurality of hydraulic fracturing pumps to the subsurface formation. The hydraulic fracturing assembly also may include a first inlet manifold positioned to provide fluid flow between a first one of the plurality of hydraulic fracturing pumps and the manifold assembly, and a second inlet manifold positioned to provide fluid flow between a second one of the plurality of hydraulic fracturing pumps and the manifold assembly. The manifold assembly may include a manifold section including a manifold passage having a manifold cross-section and a manifold axis extending longitudinally along a length of the manifold section. The manifold axis may be substantially centrally located within the manifold cross-section. The manifold assembly further may include a manifold coupling connected to the manifold section. The manifold coupling may include a manifold coupling passage having a coupling passage cross-section defining one or more of a coupling passage shape or a coupling passage size substantially in common with one or more of a manifold passage shape or a manifold passage size of the manifold cross-section. The manifold coupling also may include a manifold coupling axis parallel to the manifold axis, and a first inlet passage connected to the first inlet manifold and positioned to provide fluid flow between a first fracturing fluid output of the first hydraulic fracturing pump and the manifold passage. The first inlet passage may have a first inlet passage cross-section at least partially defining a first inlet axis extending transverse relative to the manifold axis. The manifold coupling also may include a second inlet passage connected to the second inlet manifold and positioned to provide fluid flow between a second fracturing fluid output of the second hydraulic fracturing pump and the manifold passage. The second inlet passage may have a second inlet passage cross-section at least partially defining a second inlet axis extending transverse relative to the manifold axis and not being co-linear with the first inlet axis. The first inlet axis and the second inlet axis may be oriented relative to one another, such that fracturing fluid flowing into the manifold passage from the first inlet passage and the second inlet passage promotes swirling of the fracturing fluid downstream of the manifold coupling.

According to some embodiments, a method to enhance fracturing fluid flow between a plurality of hydraulic fracturing pumps and a subsurface formation to enhance hydrocarbon production from the subsurface formation may include connecting a plurality of hydraulic fracturing pumps to a manifold assembly including a manifold section at least partially defining a manifold passage providing fluid flow between the plurality of hydraulic fracturing pumps and the subsurface formation. The method further may include causing a first fracturing fluid output from a first hydraulic fracturing pump of the plurality of hydraulic fracturing pumps and a second fracturing fluid output from a second hydraulic fracturing pump of the plurality of hydraulic fracturing pumps to enter the manifold section, such that the first fracturing fluid output and the second fracturing fluid output promote swirling of the fracturing fluid downstream of the first fracturing fluid output and the second fracturing fluid output entering the manifold passage.

According to some embodiments, a method to enhance suspension of proppants in a fracturing fluid during a high-pressure fracturing operation may include connecting a plurality of hydraulic fracturing pumps to a manifold assembly including a manifold section at least partially defining a manifold passage providing flow of fracturing fluid including proppants between the plurality of hydraulic fracturing pumps and the subsurface formation. The method further may include causing a first fracturing fluid output from a first hydraulic fracturing pump of the plurality of hydraulic fracturing pumps and a second fracturing fluid output from a second hydraulic fracturing pump of the plurality of hydraulic fracturing pumps to enter the manifold section, such that the first fracturing fluid output and the second fracturing fluid output promote swirling of the fracturing fluid and proppants downstream of the first fracturing fluid output and the second fracturing fluid output entering the manifold passage.

According to some embodiments, a method to enhance drainage of fracturing fluid from a manifold assembly following a high-pressure fracturing operation may include providing a manifold section including a manifold passage having a manifold cross-section and a manifold axis extending longitudinally along a length of the manifold section, the manifold axis being substantially centrally located within the manifold cross-section. The method further may include providing a manifold coupling including a first inlet passage connected to a first inlet manifold and positioned to provide fluid flow between a first fracturing fluid output and the manifold passage, the first inlet passage having a first inlet passage cross-section at least partially defining a first inlet axis extending transverse relative to the manifold passage. The method also may include providing a second inlet passage connected to a second inlet manifold and positioned to provide fluid flow between a second fracturing fluid output and the manifold passage, the second inlet passage having a second inlet passage cross-section at least partially defining a second inlet axis extending transverse relative to the manifold axis. The coupling passage cross-section may define an outer manifold coupling perimeter having an upper manifold coupling portion and a lower manifold coupling portion opposite the upper manifold coupling portion. The first inlet passage cross-section may define an outer inlet perimeter having an upper inlet portion and a lower inlet portion opposite the upper inlet portion. The first inlet passage may intersect the manifold passage such that the upper inlet portion of the first inlet passage substantially coincides with the upper manifold coupling portion, and the second inlet passage cross-section may define an outer inlet perimeter having an upper inlet portion and a lower inlet portion opposite the upper inlet portion. The second inlet passage may intersect the manifold coupling passage such that the lower inlet portion of the second inlet passage substantially coincides with the lower manifold coupling portion, enhancing drainage from the manifold section.

Still other aspects and advantages of these exemplary embodiments and other embodiments, are discussed in detail herein. Moreover, it is to be understood that both the foregoing information and the following detailed description provide merely illustrative examples of various aspects and embodiments, and are intended to provide an overview or framework for understanding the nature and character of the claimed aspects and embodiments. Accordingly, these and other objects, along with advantages and features herein disclosed, will become apparent through reference to the following description and the accompanying drawings. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and may exist in various combinations and permutations.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the embodiments of the present disclosure, are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure, and together with the detailed description, serve to explain principles of the embodiments discussed herein. No attempt is made to show structural details of this disclosure in more detail than can be necessary for a fundamental understanding of the embodiments discussed herein and the various ways in which they can be practiced. According to common practice, the various features of the drawings discussed below are not necessarily drawn to scale. Dimensions of various features and elements in the drawings can be expanded or reduced to more clearly illustrate embodiments of the disclosure.

FIG. 1 schematically illustrates an example hydraulic fracturing system including a plurality of hydraulic fracturing units, and including a partial perspective section view of an example manifold coupling according to embodiments of the disclosure.

FIG. 2 is a partial perspective view of a portion of an example manifold assembly according to embodiments of the disclosure.

FIG. 3 is a schematic flow diagram depicting a manifold coupling including an example of a relative lack of promotion of swirling of fracturing fluid downstream of the manifold coupling.

FIG. 4A is a partial perspective section view of an example manifold coupling according to embodiments of the disclosure.

FIG. 4B is a side section view of the example manifold coupling shown in FIG. 4A according to embodiments of the disclosure.

FIG. 5 is a schematic flow diagram depicting an example manifold coupling including an example promotion of swirling of fracturing fluid downstream of the manifold coupling according to embodiments of the disclosure.

FIG. 6A is a side section view of another example manifold coupling according to embodiments of the disclosure.

FIG. 6B is a side section view of a further example manifold coupling according to embodiments of the disclosure.

FIG. 6C is a side section view of still a further example manifold coupling according to embodiments of the disclosure.

FIG. 7 is a block diagram of an example method to enhance fracturing fluid flow between a plurality of hydraulic fracturing pumps and a subsurface formation, according to embodiments of the disclosure.

FIG. 8 is a block diagram of an example method to enhance suspension of proppants in fracturing fluid during a high-pressure fracturing operation, according to embodiments of the disclosure.

FIG. 9 is a block diagram of an example method to enhance drainage of fracturing fluid from a manifold assembly following a high-pressure fracturing operation, according to embodiments of the disclosure.

DETAILED DESCRIPTION

The drawings include like numerals to indicate like parts throughout the several views, the following description is provided as an enabling teaching of exemplary embodiments, and those skilled in the relevant art will recognize that many changes may be made to the embodiments described. It also will be apparent that some of the desired benefits of the embodiments described can be obtained by selecting some of the features of the embodiments without utilizing other features. Accordingly, those skilled in the art will recognize that many modifications and adaptations to the embodiments described are possible and may even be desirable in certain circumstances. Thus, the following description is provided as illustrative of the principles of the embodiments and not in limitation thereof.

The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. As used herein, the term “plurality” refers to two or more items or components. The terms “comprising,” “including,” “carrying,” “having,” “containing,” and “involving,” whether in the written description or the claims and the like, are open-ended terms, i.e., to mean “including but not limited to,” unless otherwise stated. Thus, the use of such terms is meant to encompass the items listed thereafter, and equivalents thereof, as well as additional items. The transitional phrases “consisting of” and “consisting essentially of,” are closed or semi-closed transitional phrases, respectively, with respect to any claims. Use of ordinal terms such as “first,” “second,” “third,” and the like in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish claim elements.

FIG. 1 schematically illustrates a top view of an example hydraulic fracturing system 10 including a plurality of hydraulic fracturing units 12 and showing an example manifold coupling 14 incorporated into an example manifold assembly 16 according to embodiments of the disclosure. The plurality of hydraulic fracturing units 12 may be configured to pump a fracturing fluid into a well at high pressure and high flow rates, so that a subterranean formation may fail and may begin to fracture in order to promote hydrocarbon production from the well. In some embodiments, the manifold coupling 14 may include first and second inlet passages 18 a and 18 b for receiving respective outputs from respective hydraulic fracturing units 12 and provide fluid flow between the outputs and a manifold passage 20 of the manifold assembly 16. As explained herein, in some embodiments, the first and second inlet passages 18 a and 18 b may be oriented and/or configured such that fracturing fluid entering the manifold assembly 16 via the first and second inlet passages 18 a and 18 b promotes swirling of the fracturing fluid downstream of the manifold coupling 14 and/or such that drainage of fracturing fluid from the manifold assembly 16 is enhanced.

In some embodiments, one or more of the hydraulic fracturing units 12 may include a hydraulic fracturing pump 22 driven by a prime mover 24, such as an internal combustion engine. For example, the prime movers 24 may include gas turbine engines (GTEs) or reciprocating-piston engines. In some embodiments, each of the hydraulic fracturing units 12 may include a directly-driven turbine (DDT) hydraulic fracturing pump 22, in which the hydraulic fracturing pump 22 is connected to one or more GTEs that supply power to the respective hydraulic fracturing pump 22 for supplying fracturing fluid at high pressure and high flow rates to the formation. For example, the GTE may be connected to a respective hydraulic fracturing pump 22 via a transmission 26 (e.g., a reduction transmission) connected to a drive shaft, which, in turn, is connected to a driveshaft or input flange of a respective hydraulic fracturing pump 22, which may be a reciprocating hydraulic fracturing pump, such as, for example, a plunger pump. In some embodiments, one or more of the hydraulic fracturing pumps 22 may include three, four, five, or more plungers, which each reciprocate linearly within a respective cylinder of a pump chamber. The hydraulic fracturing pumps 22 may include a suction port for drawing-in the fracturing fluid into the cylinder as the respective plunger moves in a first direction, and a discharge port for outputting the fracturing fluid at high-pressure and/or at a high flow rate as the respective plunger moves in a second direction opposite the first direction. The suction port and/or the discharge port may include a one-way valve preventing the output through the suction port and preventing suction through the discharge port. Other types of engine-to-pump arrangements are contemplated as will be understood by those skilled in the art.

In some embodiments, one or more of the GTEs may be a dual-fuel or bi-fuel GTE, for example, capable of being operated using of two or more different types of fuel, such as natural gas and diesel fuel, although other types of fuel are contemplated. For example, a dual-fuel or bi-fuel GTE may be capable of being operated using a first type of fuel, a second type of fuel, and/or a combination of the first type of fuel and the second type of fuel. For example, the fuel may include gaseous fuels, such as, for example, compressed natural gas (CNG), natural gas, field gas, pipeline gas, methane, propane, butane, and/or liquid fuels, such as, for example, diesel fuel (e.g., #2 diesel), bio-diesel fuel, bio-fuel, alcohol, gasoline, gasohol, aviation fuel, and other fuels as will be understood by those skilled in the art. Gaseous fuels may be supplied by CNG bulk vessels, a gas compressor, a liquid natural gas vaporizer, line gas, and/or well-gas produced natural gas. Other types and associated fuel supply sources are contemplated. The one or more prime movers 24 may be operated to provide horsepower to drive the transmission 26 connected to one or more of the hydraulic fracturing pumps 22 to safely and successfully fracture a formation during a well stimulation project or fracturing operation.

In some embodiments, the fracturing fluid may include, for example, water, proppants, and/or other additives, such as thickening agents and/or gels. For example, proppants may include grains of sand, ceramic beads or spheres, shells, and/or other particulates, and may be added to the fracturing fluid, along with gelling agents to create a slurry as will be understood by those skilled in the art. The slurry may be forced via the hydraulic fracturing pumps 16 into the formation at rates faster than can be accepted by the existing pores, fractures, faults, or other spaces within the formation. As a result, pressure in the formation may build rapidly to the point where the formation fails and begins to fracture. By continuing to pump the fracturing fluid into the formation, existing fractures in the formation may be caused to expand and extend in directions away from a wellbore, thereby creating additional flow paths for hydrocarbons to flow to the well. The proppants may serve to prevent the expanded fractures from closing or may reduce the extent to which the expanded fractures contract when pumping of the fracturing fluid is ceased. The effectiveness of the proppants may be related to the suspension of the proppants in the fracturing fluid. For example, the homogeneity and/or consistency of the suspension of the proppants in the fracturing fluid may affect the ability of the proppants to prevent the expanded fractures from closing or the extent to which the fractures contract after the pumping of the fracturing fluid is discontinued. If the homogeneity and/or consistency of the proppants in the fracturing fluid is low, the proppants may not be distributed into portions of the fractures and/or may not be relatively evenly distributed throughout the fractures, resulting in the loss of effectiveness of the proppants in those portions and fractures.

Once the well is fractured, large quantities of the injected fracturing fluid may be allowed to flow out of the well, and the water and any proppants not remaining in the expanded fractures may be separated from hydrocarbons produced by the well to protect downstream equipment from damage and corrosion. In some instances, the production stream of hydrocarbons may be processed to neutralize corrosive agents in the production stream resulting from the fracturing process.

In the example shown in FIG. 1, the hydraulic fracturing system 10 may include one or more water tanks 28 for supplying water for fracturing fluid, one or more chemical additive units 30 for supplying gels or agents for adding to the fracturing fluid, and one or more proppant tanks 32 (e.g., sand tanks) for supplying proppants for the fracturing fluid. The example fracturing system 10 shown also includes a hydration unit 34 for mixing water from the water tanks 28 and gels and/or agents from the chemical additive units 30 to form a mixture, for example, gelled water. The example shown also includes a blender 36, which receives the mixture from the hydration unit 34 and proppants via conveyers 38 from the proppant tanks 32. The blender 36 may mix the mixture and the proppants into a slurry to serve as fracturing fluid for the hydraulic fracturing system 10. Once combined, the slurry may be discharged through low-pressure hoses, which convey the slurry into two or more low-pressure lines in a low-pressure manifold 40. In the example shown, the low-pressure lines in the low-pressure manifold 40 may feed the slurry to the hydraulic fracturing pumps 22 through low-pressure suction hoses as will be understood by those skilled in the art.

The hydraulic fracturing pumps 22, driven by the respective prime movers 24 (e.g., GTEs), discharge the slurry (e.g., the fracturing fluid including the water, agents, gels, and/or proppants) as an output at high flow rates and/or high pressures through individual high-pressure discharge lines (e.g., inlet manifolds, see FIG. 2) into one or more high-pressure flow lines, sometimes referred to as “missiles,” on the fracturing manifold assembly 16. The flow from the high-pressure flow lines may be combined at the fracturing manifold assembly 16, and one or more of the high-pressure flow lines provide fluid flow to a downstream manifold 42, sometimes referred to as a “goat head.” The downstream manifold 42 delivers the slurry into a wellhead manifold 44. The wellhead manifold 44 may be configured to selectively divert the slurry to, for example, one or more wellheads 46 via operation of one or more valves. Once the fracturing process is ceased or completed, flow returning from the fractured formation discharges into a flowback manifold, and the returned flow may be collected in one or more flowback tanks as will be understood by those skilled in the art.

As schematically depicted in FIG. 1, one or more of the components of the fracturing system 10 may be configured to be portable, so that the hydraulic fracturing system 10 may be transported to a well site, assembled, operated for a period of time, at least partially disassembled, and transported to another location of another well site for use. For example, the components may be connected to and/or supported on a chassis 48, for example, a trailer and/or a support incorporated into a truck, so that they may be easily transported between well sites. In some embodiments, the prime mover 24, the transmission 26, and/or the hydraulic fracturing pump 22 may be connected to the chassis 48. For example, the chassis 48 may include a platform, the transmission 26 may be connected to the platform, and the prime mover 24 may be connected to the transmission 26. In some embodiments, the prime mover 24 may be connected to the transmission 26 without also connecting the prime mover 24 directly to the platform, which may result in fewer support structures being needed for supporting the prime mover 24, transmission 26, and/or hydraulic fracturing pump 22 on the chassis 48.

As shown in FIG. 1, some embodiments of the hydraulic fracturing system 10 may include one or more fuel supplies 50 for supplying the prime movers 24 and any other fuel-powered components of the hydraulic fracturing system 10, such as auxiliary equipment, with fuel. The fuel supplies 50 may include gaseous fuels, such as compressed natural gas (CNG), natural gas, field gas, pipeline gas, methane, propane, butane, and/or liquid fuels, such as, for example, diesel fuel (e.g., #2 diesel), bio-diesel fuel, bio-fuel, alcohol, gasoline, gasohol, aviation fuel, and other fuels. Gaseous fuels may be supplied by CNG bulk vessels, such as fuel tanks coupled to trucks, a gas compressor, a liquid natural gas vaporizer, line gas, and/or well-gas produced natural gas. The fuel may be supplied to the hydraulic fracturing units 12 by one of more fuel lines supplying the fuel to a fuel manifold and unit fuel lines between the fuel manifold and the hydraulic fracturing units 12. Other types and associated fuel supply sources and arrangements are contemplated as will be understood by those skilled in the art.

As shown in FIG. 1, some embodiments also may include one or more data centers 52 configured to facilitate receipt and transmission of data communications related to operation of one or more of the components of the hydraulic fracturing system 10. Such data communications may be received and/or transmitted via hard-wired communications cables and/or wireless communications, for example, according to known communications protocols. For example, the data centers 52 may contain at least some components of a hydraulic fracturing control assembly, such as a supervisory controller configured to receive signals from components of the hydraulic fracturing system 10 and/or communicate control signals to components of the hydraulic fracturing system 10, for example, to at least partially control operation of one or more components of the hydraulic fracturing system 10, such as, for example, the prime movers 24, the transmissions 26, and/or the hydraulic fracturing pumps 22 of the hydraulic fracturing units 12, the chemical additive units 30, the hydration units 34, the blender 36, the conveyers 38, the low-pressure manifold 40, the downstream manifold 42, the wellhead manifold 44, and/or any associated valves, pumps, and/or other components of the hydraulic fracturing system 10.

FIG. 2 is a partial perspective view of a portion of an example manifold assembly 16 according to embodiments of the disclosure. As shown in FIGS. 1 and 2, each of the hydraulic fracturing units 12 may be configured to supply fracturing fluid under high pressure and/or high flow rates to the manifold assembly 16, which provides a flow passage between the respective hydraulic fracturing pumps 16 and the wellhead manifold 44 (see FIG. 1) to supply the fracturing fluid under high pressure to a wellbore during a fracturing operation. As shown in FIGS. 1 and 2, each of the respective hydraulic fracturing pumps 16 may provide a supply of hydraulic fracturing fluid to the manifold assembly 16 (e.g., a high-pressure manifold assembly) via a respective flow iron section 54, for example, flow iron sections 54 a, 54 b, 54 c, and 54 d shown in FIG. 2. Each of the flow iron sections 54 may include respective passages that may be connected at a first end to an output of a respective one of the hydraulic fracturing pumps 16 and at an opposite, remote or second end, a respective manifold coupling 14, for example, manifold couplings 14 a and 14 b shown in FIG. 2. As shown in FIG. 2, a first one of the manifold couplings 14 a may be an end coupling, which acts as a first coupling in a sequence of a plurality of manifold couplings 14, for example, with a remainder of the manifold couplings 14 being downstream relative to the end coupling. In some embodiments, the end coupling may have the same (or similar) configuration as the remainder of the downstream manifold couplings 14, and an end plate 56 may be connected to the end coupling to close a manifold passage in the manifold coupling. In some embodiments, the end plate 56 may include a port to receive a coupling 58 and/or a valve 60 configured to provide pressure relief and/or to prime the manifold assembly 16.

In some embodiments, the manifold assembly 16 may be configured to provide a common conduit to receive fracturing fluid at high pressure and/or high flow rates from the hydraulic fracturing pumps 22 and convey the fracturing fluid to the wellbore at a desired pressure and/or flow rate. The manifold assembly 16 may include a plurality of the manifold couplings 14 that receive the respective fracturing fluid outputs from the hydraulic fracturing pumps 22 and consolidate the fracturing fluid into the manifold assembly 16. In some embodiments, one or more of the manifold couplings 14 may be configured to receive fracturing fluid outputs from two, three, four, or more of the hydraulic fracturing pumps 22.

As shown in FIG. 2, in some embodiments, the manifold assembly 16 may include a plurality of manifold sections 62, for example, manifold sections 62 a and 62 b shown in FIG. 2, and the manifold sections 62 may be connected to one another via the manifold couplings 14. For example, as shown, the first manifold coupling 14 a is connected to a first end of a first manifold section 62 a of the plurality of manifold sections 62, and a second end opposite the first end of the first manifold section 62 a is connected to the second manifold coupling 14 b. A first end of a second manifold section 62 b of the plurality of manifold sections 62 is connected to the second manifold coupling 14 b, and a second end opposite the first end of the second manifold section 62 b may be connected to another one of the manifold couplings 14. In some embodiments, the manifold assembly 16 may include two or more of the manifold sections 62, and the manifold sections 62 may be connected to one another in an end-to-end manner via two or more of the manifold couplings 14, thereby providing fluid flow between a plurality of the hydraulic fracturing pumps 22 (e.g., hydraulic fracturing pumps 22 a, 22 b, 22 c, 22 d, etc., as shown) of a plurality of corresponding hydraulic fracturing units 12 and the wellhead manifold 44 (see FIG. 1).

FIG. 3 is a schematic flow diagram depicting a manifold coupling 14 including an example of a relative lack of promotion of swirling of fracturing fluid downstream of the manifold coupling 14. As shown in FIG. 3, two manifold sections 62 a and 62 b are connected to one another via a manifold coupling 14. Each of the manifold sections 62 a and 62 b includes a manifold passage 20 (20 a and 20 b as shown in FIG. 3) having a manifold cross-section and a manifold axis MX extending longitudinally along a length of the manifold section 62, and the manifold axis MX is substantially centrally located within the manifold cross-section. The manifold coupling 14 is connected to each of the manifold sections 62 a and 62 b, and the manifold coupling 14 includes a manifold coupling passage 64 having a coupling passage cross-section defining a coupling passage shape and a coupling passage size substantially in common with the manifold cross-section and the manifold axis MX of the manifold passage 20 of each of the manifold sections 62 a and 62 b. As shown in FIG. 3, the manifold coupling 14 includes a first inlet passage 18 a positioned to provide fluid flow between a first fracturing fluid output of a first hydraulic fracturing pump and the manifold passage 20. As shown in FIG. 3, the first inlet passage 18 a has a first inlet passage cross-section defining a first inlet axis X1 extending transverse relative to the manifold axis MX of the manifold sections 62 a and 62 b. The manifold coupling 14 shown in FIG. 3 also includes a second inlet passage 18 b positioned opposite the first inlet passage 18 a to provide fluid flow between a second fracturing fluid output of a second hydraulic fracturing pump and the manifold passage 20. The second inlet passage 18 b has a second inlet passage cross-section defining a second inlet axis X2 extending transverse relative to the manifold axis MX and co-linear with respect to the first inlet axis X1.

In some embodiments, the manifold sections 62 may have different lengths, different inside diameters, and/or different manifold coupling inlet passage orientations. In some embodiments, the manifold sections 62 and/or manifold couplings 14 may be configured to have a manifold passage 20 and manifold coupling passage 64 having a cross-section that is of a substantially constant cross-sectional size and a substantially constant cross-sectional shape, which may form a manifold assembly 16 sometimes referred to as a “mono-bore” manifold. In some such embodiments, the manifold sections 62 and manifold couplings 14 consolidate the fracturing fluid flow from the hydraulic fracturing pumps 22. Applicant has recognized that in some such embodiments, the manifold assembly 16 may damp pressure pulsations resulting from the outputs of the hydraulic fracturing pumps 22. The pressure pulsations are generated during operation of the hydraulic fracturing pumps 22 and the pressure pulsations may travel downstream into the manifold assembly 16, including the manifold sections 62. Each of the hydraulic fracturing pumps 22 may generate cyclic pressure pulsations, each having distinct amplitudes and/or distinct frequencies. Damping of the pressure pulsations by the manifold assembly 16 may result from one or more of the increased volume of fracturing fluid trapped inside the manifold assembly 16, allowing some energy dissipation of the pressure pulses, the spacing and/or orientation of the inlet passages of the manifold couplings 14, mechanical damping around the manifold couplings 14 and/or manifold sections 62, or the respective lengths, configurations, and/or materials of the fracturing fluid conduits (e.g., the flow iron sections 54, the inlet passages 18, and/or the manifold sections 62), which may affect acoustic responses of the manifold assembly 16.

During operation of the hydraulic fracturing pumps 22, in some embodiments, cyclic movement of the plungers may generate the high-pressure pulsations, which may increase energy intensity inside the manifold assembly 16, for example, in relation to the manifold couplings 14 at the inlet passages 18. The energy intensity may induce high vibration amplitudes that, in turn, may increase the possibility of fatigue stress failures in components of the hydraulic fracturing system 10, for example, including the hydraulic fracturing pumps 22, the manifold assembly 16, including the related connections.

Without wishing to be bound by theory, Applicant believes that a contributing factor to the increased energy intensity may result from the manner in which the manifold couplings 14 are spaced and oriented relative to the manifold sections 62. For example, inlet passages 18 of the manifold couplings 14 may be aligned with the manifold passage 20 of the manifold sections 62, such that the respective centers of the inlet passages 18 are aligned with the center of the manifold passage 20, for example, as shown in FIG. 3. Applicant believes that this arrangement may result in a magnification of the pressure pulsation force, possibly because orientation of the inlet passages 18, opposite and aligned with one another relative to the manifold passage 20, may result in flow of fracturing fluid from the respective inlet passages 18 into the manifold passage 20 colliding directly with or obstructing one another, for example, once subsequent pressure pulses and/or flow pulses from upstream relative to the manifold coupling 14 reach the manifold coupling 14 and are combined with the fracturing fluid flowing into the manifold coupling 14 via the inlet passages 18. This, in turn, may create relatively large collisions of high-pressure fracturing fluids, which may have similar momentum, and this may result in a relatively high concentration of pressure increase at the inlet passages 18 of the manifold couplings 14.

Without wishing to be bound by theory, Applicant believes that fluid flow turbulence may be disturbed when the inlet passages of a manifold coupling 14 are in a concentric and/or aligned configuration. It is believed by Applicant that this may result in the generation of relatively smaller-scaled vortex flow or “swirls”, which may, in turn, decrease any fluid viscous damping of the pressure pulses and related fluid energy. This, in turn, may result in inducing and/or amplifying vibration in the manifold assembly 16.

As schematically depicted in FIG. 3, upstream flow 66 of the fracturing fluid passes through the manifold coupling passage 64 of the manifold coupling 14 and continues as downstream flow 68 after passing through the manifold coupling 14. A first output flow 70 a from a first output of a first hydraulic fracturing pump flows into the manifold coupling 14 via a first flow iron section 54 a and a first inlet passage 18 a of the manifold coupling 14. Similarly, a second output flow 70 b from a second output of a second hydraulic fracturing pump flows into the manifold coupling 14 via a second flow iron section 54 b and a second inlet passage 18 b of the manifold coupling 14. As schematically depicted in FIG. 3, the upstream flow 66 and the downstream flow 68 are such that the flow of the fracturing fluid is not significantly swirling and thus is not significantly turbulent. Entry of the first output flow 70 a and the second output flow 70 b into the manifold coupling 14 does not cause significant swirling or turbulence in the downstream flow 68. This, in turn, may result in inducing and/or amplifying vibration in the manifold assembly 16.

FIG. 4A is a partial perspective section view of an example manifold coupling 14 according to embodiments of the disclosure, and FIG. 4B is a side section view of the example manifold coupling 14 shown in FIG. 4A. In some embodiments, as shown in FIGS. 4A and 4B, the manifold coupling 14 may be connected to one or more manifold sections 62 (see FIG. 2), and the manifold coupling 14 may include a manifold coupling passage 64 having a coupling passage cross-section defining one or more of a coupling passage shape or a coupling passage size substantially in common with the manifold passage shape or a manifold passage size of the manifold cross-section of one or more of the manifold sections 62. In some embodiments, a manifold coupling axis MCX of the manifold coupling 14 may be substantially parallel to the manifold axis MX of the manifold passage 20 of one or more of the manifold sections 62 to which the manifold coupling 14 is attached. As shown, some embodiments of the manifold coupling 14 may include a first inlet passage 18 a positioned to provide fluid flow between a first fracturing fluid output of a first hydraulic fracturing pump and the manifold passage 20. The first inlet passage 18 a may have a first inlet passage cross-section at least partially defining a first inlet axis X1 extending transverse (e.g., perpendicular) relative to the manifold axis MX of the one or more manifold sections 62. As shown, the manifold coupling 14 may also include a second inlet passage 18 b positioned opposite the first inlet passage 18 a to provide fluid flow between a second fracturing fluid output of a second hydraulic fracturing pump and the manifold passage 20 of the one or more manifold sections 62. The second inlet passage 18 b may have a second inlet passage cross-section at least partially defining a second inlet axis X2 extending transverse (e.g., perpendicular) relative to the manifold axis MX of the one or more manifold sections 62.

As shown in FIGS. 4A and 4B, in some embodiments of the manifold coupling 14, the first inlet passage 18 a and the second inlet passage 18 b may be oriented relative to one another such that the first inlet axis X1 and the second inlet axis X2 are not co-linear relative to one another. For example, in some embodiments, the first inlet passage 18 a and the second inlet passage 18 b may be oriented relative to one another, such that the first inlet axis X1 and the second inlet axis X2 are oriented relative to one another so that fracturing fluid flowing into the manifold passage 20 from the first inlet passage 18 a and the second inlet passage 18 b promotes swirling of the fracturing fluid downstream of the manifold coupling 14. In some embodiments, the first inlet axis X1 and the second inlet axis X2 lie in a plane perpendicular to the manifold axis MX, for example, as shown in FIGS. 4A and 4B. In some embodiments, the first inlet axis X1 and the second inlet axis X2 are parallel and offset relative to one another, for example, as shown in FIGS. 4A and 4B (see also FIGS. 6A and 6C).

Without wishing to be bound by theory, Applicant believes that increasing the free vortex flow and forced vortex flow in the manifold passage 20 of the manifold assembly 16 may result in increasing the difference between the radial pressure and/or axial pressure along the wall of the manifold passage 20 and the radial pressure and/or axial pressure at the centerline region of the manifold passage 20. It is believed by Applicant that this may permit the fracturing fluid to dissipate pressure energy, for example, as the fracturing fluid swirls within the manifold passage 20, releasing at least a portion of the pressure energy in the form of, for example, heat and/or viscous shear of the fracturing fluid. This, in turn, may result in improved and/or more efficient pressure pulsation damping inside the manifold passage 20 of the manifold assembly 16. This may result in suppression and/or dissipation of vibration in the manifold assembly 16.

In some embodiments, the promotion of swirling of the fracturing fluid in the manifold passage 20 and/or the manifold assembly 16 in general may improve the level of proppant suspension in the fracturing fluid. For example, the manner in which the fracturing fluid flows through the manifold assembly 16 may affect the homogeneity and/or consistency of the suspension of the proppants in the fracturing fluid pumped through the manifold assembly 16. To the extent that some manifold assemblies may not promote or may inhibit swirling of the fracturing fluid, such manifold assemblies may hinder the homogeneous or consistent suspension of proppants in the fracturing fluid. This may reduce the effectiveness of the proppants.

In some embodiments, the first inlet axis X1 and the second inlet axis X2 may be oriented relative to one another such that fracturing fluid flowing into the manifold passage 20 from the first inlet passage 18 a and the second inlet passage 18 b promotes swirling of the fracturing fluid downstream of the manifold coupling 14, for example, as schematically depicted by the arrows S shown in FIG. 4B. For example, FIG. 5 is a schematic flow diagram depicting an example manifold coupling 14 including an example promotion of swirling of fracturing fluid downstream of the manifold coupling 14 according to embodiments of the disclosure. As shown in FIG. 5, two manifold sections 62 a and 62 b are connected to one another via a manifold coupling 14 according to embodiments of the disclosure. Each of the manifold sections 62 a and 62 b includes a manifold passage 20 (e.g., manifold passages 20 a and 20 b shown in FIG. 5) having a manifold cross-section and a manifold axis MX extending longitudinally along a length of the manifold section 62, and the manifold axis MX may be substantially centrally located within the manifold cross-section. In some embodiments, the manifold coupling 14 may be connected to each of the manifold sections 62 a and 62 b, and the manifold coupling 14 may include a manifold coupling passage 64 having a coupling passage cross-section at least partially defining a coupling passage shape and/or a coupling passage size substantially in common with the manifold cross-section and the manifold axis MX of the manifold passage 20 of one or more of the manifold sections 62 a and 62 b. As shown in FIG. 5, the manifold coupling 14 may include a first inlet passage 18 a positioned to provide fluid flow between a first fracturing fluid output of a first hydraulic fracturing pump and the manifold passage 20. The first inlet passage 18 a may have a first inlet passage cross-section at least partially defining a first inlet axis X1 extending transverse (e.g., perpendicular) relative to the manifold axis MX of the manifold sections 62 a and 62 b. The manifold coupling 14 shown in FIG. 5 also may include a second inlet passage 18 b positioned opposite the first inlet passage 18 a to provide fluid flow between a second fracturing fluid output of a second hydraulic fracturing pump and the manifold passage 20. The second inlet passage 18 b may have a second inlet passage cross-section defining a second inlet axis X2 extending transverse (e.g., perpendicular) relative to the manifold axis MX.

As schematically depicted in FIG. 5, upstream flow 66 of the fracturing fluid passes through the manifold coupling passage 64 of the manifold coupling 14 and continues as downstream flow 68 after passing through the manifold coupling 14. A first output flow 70 a from a first output of a first hydraulic fracturing pump flows into the manifold coupling 14 via a first flow iron section 54 a and a first inlet passage 18 a of the manifold coupling 14. Similarly, a second output flow 70 b from a second output of a second hydraulic fracturing pump flows into the manifold coupling 14 via a second flow iron section 54 b and a second inlet passage 18 b of the manifold coupling 14. As schematically depicted in FIG. 5, the upstream flow 66 and the downstream flow 68 are such that swirling of the flow of the fracturing fluid is promoted, for example, as schematically depicted in FIGS. 4B and 5, for example, resulting in the downstream flow 68 flow of the fracturing fluid being significantly turbulent. Thus, entry of the first output flow 70 a and the second output flow 70 b into the manifold coupling 14 results in causing significant swirling or turbulence in the downstream flow 68.

As shown in FIGS. 4A and 4B, in some embodiments of the manifold coupling 14, the coupling passage cross-section of the manifold coupling 14 may define an outer manifold coupling perimeter 72 having an upper manifold coupling portion 74 and a lower manifold coupling portion 76 opposite the upper manifold coupling portion 74. In some embodiments, the cross-section of the first inlet passage 18 a may at least partially define an outer inlet perimeter 78 having an upper inlet portion 80 and a lower inlet portion 82 opposite the upper inlet portion 80. The first inlet passage 18 a may intersect the manifold coupling passage 64 such that the upper inlet portion 80 of the first inlet passage 18 a substantially coincides with the upper manifold coupling portion 74. In some embodiments, the cross-section of the second inlet passage 18 b may at least partially define an outer inlet perimeter 84 having an upper inlet portion 86 and a lower inlet portion 88 opposite the upper inlet portion 86. In some embodiments, the second inlet passage 18 b may intersect the manifold coupling passage 64 such that the lower inlet portion 88 of the second inlet passage 18 b substantially coincides with the lower manifold coupling portion 76. In some embodiments, this may enhance drainage from the manifold section 62.

For example, in embodiments consistent with those shown in FIGS. 4A, 4B, and 5 (see also FIG. 6B and FIG. 6C), drainage of fracturing fluid from the manifold assembly 16 following a fracturing operation may be enhanced. Because the lower portion of one of the inlet passages 18 is at or below the level of the lowest portion of the manifold passage 20, it may reduce the likelihood or prevent fracturing fluid, including in some instances proppants, from remaining in the manifold assembly 16, the manifold couplings 14, and/or the manifold sections 62. This may reduce payload weight and/or weight distribution imbalances while transporting the components of the manifold assembly 16 to another location for preforming another fracturing operation. This also may inhibit corrosion of components of the manifold assembly 16 that may occur if fracturing fluid remains in the manifold assembly 16. Fracturing fluids may include cementitious and/or corrosive materials that may reduce the service life, damage, and/or create maintenance issues if they remain in the manifold assembly 16 for prolonged periods. In some embodiments, the manifold coupling 14 may reduce the likelihood or prevent such occurrences.

As shown in FIGS. 4A and 5, in some embodiments, the manifold coupling 14 may include three pairs of opposing sides 90 a and 90 b, 92 a and 92 b, and 94 a and 94 b, substantially forming a rectangular prism. The manifold passage 20 may pass through a first pair of the opposing sides 90 a and 90 b, and a second pair of the opposing sides 92 a and 92 b may be substantially perpendicular relative to the first pair of opposing sides 90 a and 90 b. The first inlet passage 18 a may extend from a first opposing side 92 a of the second pair of opposing sides 92 a and 92 b to the manifold passage 20, and the second inlet passage 18 b may extend from a second opposing side 92 b of the second pair of opposing sides 92 a and 92 b to the manifold passage 20.

As shown in FIGS. 2 and 4A, in some embodiments, the first flow iron section 54 a may include a first inlet manifold 96 a connected to the manifold coupling 14 and positioned to provide a first fluid flow between a first fracturing fluid output of a first hydraulic fracturing pump and the first inlet passage 18 a. In some embodiments, a first coupling flange 98 a may connect the first inlet manifold 96 a to the manifold coupling 14. For example, the manifold coupling 14 may include a first coupling recess 100 a in which the first coupling flange 98 a may be at least partially received. The first coupling flange 98 a and/or the first coupling recess 100 a may have a substantially circular cross-section perpendicular to the first inlet axis X1. In some embodiments, a first coupling seal 102 a may be positioned to provide a fluid-tight seal between the first coupling flange 98 a and the first coupling recess 100 a.

In some embodiments, as shown in FIGS. 2 and 4A, the second flow iron section 54 b may include a second inlet manifold 96 b connected to the manifold coupling 14 and positioned to provide a second fluid flow between a second fracturing fluid output of a second hydraulic fracturing pump and the second inlet passage 18 b. In some embodiments, a second coupling flange 98 b may connect the second inlet manifold 96 b to the manifold coupling 14. For example, the manifold coupling 14 may include a second coupling recess 100 b (e.g., substantially opposite the first coupling recess 100 a) in which the second coupling flange 98 b may be at least partially received. The second coupling flange 98 b and/or the second coupling recess 100 b may have a substantially circular cross-section perpendicular to the second inlet axis X2. In some embodiments, a second coupling seal 102 b may be positioned to provide a fluid-tight seal between the second coupling flange 98 b and the second coupling recess 100 b.

FIG. 6A is a side section view of another example manifold coupling 14 according to embodiments of the disclosure. As shown in FIG. 6A, in some embodiments, the manifold coupling 14 may be configured such that the first inlet axis X1 and the second inlet axis X2 of the first inlet passage 18 a and the second inlet passage 18 b, respectively, are parallel and offset relative to one another. As shown in FIG. 6A, the first inlet axis X1 and the second inlet axis X2 may be oriented relative to one another such that fracturing fluid flowing into manifold coupling passage 64 from the first inlet passage 18 a and the second inlet passage 18 b promotes swirling of the fracturing fluid downstream of the manifold coupling 14, for example, as schematically depicted by the arrows S shown in FIG. 6A.

FIG. 6B is a side section view of a further example manifold coupling 14 according to embodiments of the disclosure. As shown in FIG. 6B, in some embodiments, the manifold coupling 14 may be configured such that the first inlet axis X1 and the second inlet axis X2 of the first inlet passage 18 a and the second inlet passage 18 b, respectively, are not parallel relative to one another. As shown in FIG. 6B, in some embodiments, the first inlet axis X1 and the second inlet axis X2 lie in a common plane, but are not parallel relative to one another. As shown in FIG. 6B, the first inlet axis X1 and the second inlet axis X2 may be oriented relative to one another such that fracturing fluid flowing into manifold coupling passage 64 from the first inlet passage 18 a and the second inlet passage 18 b promotes swirling of the fracturing fluid downstream of the manifold coupling 14, for example, as schematically depicted by the arrows S shown in FIG. 6B. In some embodiments, the first inlet axis X1 and the second inlet axis X2 may be skew relative to one another, for example, being neither parallel to one another nor intersecting one another (e.g., not lying in a common plane relative to one another), but oriented relative to one another such that fracturing fluid flowing into manifold coupling passage 64 from the first inlet passage 18 a and the second inlet passage 18 b promotes swirling of the fracturing fluid downstream of the manifold coupling 14.

FIG. 6C is a side section view of still a further example manifold coupling 14 according to embodiments of the disclosure. As shown in FIG. 6C, in some embodiments, the manifold coupling 14 may be configured such that the first inlet axis X1 and the second inlet axis X2 of the first inlet passage 18 a and the second inlet passage 18 b, respectively, are parallel and offset relative to one another. For example, in some embodiments, as shown in FIG. 6C, a manifold coupling cross-section of the manifold coupling 14 perpendicular to the manifold axis MX may at least partially define two pairs of opposing sides, and the first inlet axis X1 and the second inlet axis X2 are oblique with respect to one or more of the two pairs of opposing sides. As shown in FIG. 6C, the first inlet axis X1 and the second inlet axis X2 may be oriented relative to one another such that fracturing fluid flowing into manifold coupling passage 64 from the first inlet passage 18 a and the second inlet passage 18 b promotes swirling of the fracturing fluid downstream of the manifold coupling 14, for example, as schematically depicted by the arrows S shown in FIG. 6C.

FIG. 7, FIG. 8, and FIG. 9 show block diagrams of example methods 700, 800, and 900 according to embodiments of the disclosure, illustrated as respective collections of blocks in logical flow graphs, which represent a sequence of operations. FIG. 7 is a block diagram of an example method 700 to enhance fracturing fluid flow between a plurality of hydraulic fracturing pumps and a subsurface formation to enhance hydrocarbon production from the subsurface formation, according to embodiments of the disclosure. FIG. 8 is a block diagram of an example method 800 to enhance suspension of proppants in fracturing fluid during a high-pressure fracturing operation, according to embodiments of the disclosure. FIG. 9 is a block diagram of an example method 900 to enhance drainage of fracturing fluid from a manifold assembly following a high-pressure fracturing operation, according to embodiments of the disclosure. For each of the respective example methods, the order in which the operations are described is not intended to be construed as a limitation, and any number of the described blocks may be combined in any order and/or in parallel to implement the method.

FIG. 7 is a block diagram of an example method 700 to enhance fracturing fluid flow between a plurality of hydraulic fracturing pumps and a subsurface formation to enhance hydrocarbon production from the subsurface formation, according to embodiments of the disclosure. As shown in FIG. 7, the example method 700, at 702, may include connecting a plurality of hydraulic fracturing pumps to a manifold assembly including a manifold section at least partially defining a manifold passage providing fluid flow between the plurality of hydraulic fracturing pumps and the subsurface formation.

At 704, the example method 700 may include causing a first fracturing fluid output from a first hydraulic fracturing pump of the plurality of hydraulic fracturing pumps and a second fracturing fluid output from a second hydraulic fracturing pump of the plurality of hydraulic fracturing pumps to enter the manifold section, such that the first fracturing fluid output and the second fracturing fluid output promote swirling of the fracturing fluid downstream of the first fracturing fluid output and the second fracturing fluid output entering the manifold passage.

For example, causing the first fracturing fluid output and the second fracturing fluid output to enter the manifold section may include providing a first inlet passage connected to a first inlet manifold and positioned to provide fluid flow between the first fracturing fluid output and the manifold passage. The first inlet passage may have a first inlet passage cross-section at least partially defining a first inlet axis extending transverse relative to the manifold passage. Causing the first fracturing fluid output and the second fracturing fluid output to enter the manifold section may include providing a second inlet passage connected to a second inlet manifold and positioned to provide fluid flow between the second fracturing fluid output and the manifold passage. The second inlet passage may have a second inlet passage cross-section at least partially defining a second inlet axis extending transverse relative to the manifold axis and not being co-linear with the first inlet axis. For example, the first inlet axis and the second inlet axis may lie in a plane perpendicular to the manifold axis. For example, the first inlet axis and the second inlet axis may be parallel and offset relative to one another, for example, as described herein.

In some examples of the method 700, the coupling passage cross-section may at least partially define an outer manifold coupling perimeter having opposite manifold coupling portions. The first inlet passage cross-section may at least partially define an outer inlet perimeter having opposite inlet portions. The first inlet passage may intersect the manifold coupling passage such that one of the opposite inlet portions of the first inlet passage substantially coincides with a first manifold coupling portion of the opposite manifold coupling portions. The second inlet passage cross-section may at least partially define an outer inlet perimeter having opposite inlet portions. The second inlet passage may intersect the manifold coupling passage such that one of the opposite inlet portions of the second inlet passage substantially coincides with a second manifold coupling portion of the opposite manifold coupling portions. The first inlet axis and the second inlet axis may lie in a common plane without being parallel relative to one another. The first inlet axis and the second inlet axis may be skew relative to one another, for example, as described herein.

FIG. 8 is a block diagram of an example method 800 to enhance suspension of proppants in fracturing fluid during a high-pressure fracturing operation, according to embodiments of the disclosure. At 802, the example method 800 may include connecting a plurality of hydraulic fracturing pumps to a manifold assembly including a manifold section at least partially defining a manifold passage providing flow of fracturing fluid including proppants between the plurality of hydraulic fracturing pumps and the subsurface formation.

At 804, the example method 800 may include causing a first fracturing fluid output from a first hydraulic fracturing pump of the plurality of hydraulic fracturing pumps and a second fracturing fluid output from a second hydraulic fracturing pump of the plurality of hydraulic fracturing pumps to enter the manifold section, such that the first fracturing fluid output and the second fracturing fluid output promote swirling of the fracturing fluid and proppants downstream of the first fracturing fluid output and the second fracturing fluid output entering the manifold passage. For example, causing the first fracturing fluid output and the second fracturing fluid output to enter the manifold section may include providing a first inlet passage connected to a first inlet manifold and positioned to provide fluid flow between the first fracturing fluid output and the manifold passage, and the first inlet passage may have a first inlet passage cross-section at least partially defining a first inlet axis extending transverse relative to the manifold passage. Causing the first fracturing fluid output and the second fracturing fluid output to enter the manifold section further may include providing a second inlet passage connected to a second inlet manifold and positioned to provide fluid flow between the second fracturing fluid output and the manifold passage, and the second inlet passage may have a second inlet passage cross-section at least partially defining a second inlet axis extending transverse relative to the manifold axis and not being co-linear with the first inlet axis, for example, as described herein.

In some examples of the method 800, the coupling passage cross-section may at least partially define an outer manifold coupling perimeter having opposite manifold coupling portions. The first inlet passage cross-section may at least partially define an outer inlet perimeter having opposite inlet portions. The first inlet passage may intersect the manifold coupling passage such that one of the opposite inlet portions of the first inlet passage substantially coincides with a first manifold coupling portion of the opposite manifold coupling portions. The second inlet passage cross-section may at least partially define an outer inlet perimeter having opposite inlet portions. The second inlet passage may intersect the manifold coupling passage such that one of the opposite inlet portions of the second inlet passage substantially coincides with a second manifold coupling portion of the opposite manifold coupling portions.

FIG. 9 is a block diagram of an example method 900 to enhance drainage of fracturing fluid from a manifold assembly following a high-pressure fracturing operation, according to embodiments of the disclosure. At 902, the example method 900 may include providing a manifold section including a manifold passage having a manifold cross-section and a manifold axis extending longitudinally along a length of the manifold section, the manifold axis being substantially centrally located within the manifold cross-section. The example method 900 further ay include providing a manifold coupling including a first inlet passage connected to a first inlet manifold and positioned to provide fluid flow between a first fracturing fluid output and the manifold passage. The first inlet passage may have a first inlet passage cross-section at least partially defining a first inlet axis extending transverse relative to the manifold passage. The manifold coupling further may include a second inlet passage connected to a second inlet manifold and positioned to provide fluid flow between a second fracturing fluid output and the manifold passage. The second inlet passage may have a second inlet passage cross-section at least partially defining a second inlet axis extending transverse relative to the manifold axis. In some embodiments of the method 900, the coupling passage cross-section may at least partially define an outer manifold coupling perimeter having an upper manifold coupling portion and a lower manifold coupling portion opposite the upper manifold coupling portion. The first inlet passage cross-section may at least partially define an outer inlet perimeter having an upper inlet portion and a lower inlet portion opposite the upper inlet portion. The first inlet passage may intersect the manifold coupling passage such that the upper inlet portion of the first inlet passage substantially coincides with the upper manifold coupling portion. The second inlet passage cross-section may at least partially define an outer inlet perimeter having an upper inlet portion and a lower inlet portion opposite the upper inlet portion, and the second inlet passage may intersect the manifold coupling passage such that the lower inlet portion of the second inlet passage substantially coincides with the lower manifold coupling portion, enhancing drainage from the manifold section.

Having now described some illustrative embodiments of the disclosure, it should be apparent to those skilled in the art that the foregoing is merely illustrative and not limiting, having been presented by way of example only. Numerous modifications and other embodiments are within the scope of one of ordinary skill in the art and are contemplated as falling within the scope of the disclosure. In particular, although many of the examples presented herein involve specific combinations of method acts or system elements, it should be understood that those acts and those elements may be combined in other ways to accomplish the same objectives. Those skilled in the art should appreciate that the parameters and configurations described herein are exemplary and that actual parameters and/or configurations will depend on the specific application in which the systems, methods, and or aspects or techniques of the disclosure are used. Those skilled in the art should also recognize or be able to ascertain, using no more than routine experimentation, equivalents to the specific embodiments of the disclosure. It is, therefore, to be understood that the embodiments described herein are presented by way of example only and that, within the scope of any appended claims and equivalents thereto, the disclosure may be practiced other than as specifically described.

This is a continuation of U.S. Non-Provisional application Ser. No. 17/303,150, filed May 21, 2021, titled “METHODS, SYSTEMS, AND DEVICES TO ENHANCE FRACTURING FLUID DELIVERY TO SUBSURFACE FORMATIONS DURING HIGH-PRESSURE FRACTURING OPERATIONS,” which is a continuation of U.S. Non-Provisional application Ser. No. 17/303,146, filed May 21, 2021, titled “METHODS, SYSTEMS, AND DEVICES TO ENHANCE FRACTURING FLUID DELIVERY TO SUBSURFACE FORMATIONS DURING HIGH-PRESSURE FRACTURING OPERATIONS,” which claims priority to and the benefit of U.S. Provisional Application No. 63/201,721, filed May 11, 2021, titled “METHODS, SYSTEMS, AND DEVICES TO ENHANCE FRACTURING FLUID DELIVERY TO SUBSURFACE FORMATIONS DURING HIGH-PRESSURE FRACTURING OPERATIONS,” and U.S. Provisional Application No. 62/705,850, filed Jul. 17, 2020, titled “METHODS, SYSTEMS, AND DEVICES FOR ENERGY DISSIPATION AND PROPPANT SUSPENSION BY INDUCED VORTEX FLOW IN MONO-BORE MANIFOLDS,” the disclosures of which are incorporated herein by reference in their entirety.

Furthermore, the scope of the present disclosure shall be construed to cover various modifications, combinations, additions, alterations, etc., above and to the above-described embodiments, which shall be considered to be within the scope of this disclosure. Accordingly, various features and characteristics as discussed herein may be selectively interchanged and applied to other illustrated and non-illustrated embodiment, and numerous variations, modifications, and additions further may be made thereto without departing from the spirit and scope of the present disclosure as set forth in the appended claims. 

What is claimed is:
 1. A manifold assembly to enhance fracturing fluid delivery to a subsurface formation for hydrocarbon production from the subsurface formation, the manifold assembly comprising: a manifold section comprising a manifold passage having a manifold cross-section and a manifold axis extending longitudinally along a length of the manifold section, the manifold axis being substantially centrally located within the manifold cross-section; and a manifold coupling connected to the manifold section, the manifold coupling comprising: a manifold coupling passage having a coupling passage cross-section defining one or more of a coupling passage shape or a coupling passage size substantially in common with one or more of a manifold passage shape or a manifold passage size of the manifold cross-section; a manifold coupling axis parallel to the manifold axis; a first inlet passage positioned to provide fluid flow between a first fracturing fluid output of a first hydraulic fracturing pump and the manifold passage, the first inlet passage having a first inlet passage cross-section at least partially defining a first inlet axis extending transverse relative to the manifold axis; and a second inlet passage positioned opposite the first inlet passage to provide fluid flow between a second fracturing fluid output of a second hydraulic fracturing pump and the manifold passage, the second inlet passage having a second inlet passage cross-section at least partially defining a second inlet axis extending transverse relative to the manifold axis, the first inlet axis and the second inlet axis positioned to lie in a plane substantially perpendicular to the manifold axis.
 2. The manifold assembly of claim 1, wherein: the coupling passage cross-section defines an outer manifold coupling perimeter having opposite manifold coupling portions; the first inlet passage cross-section defines an outer inlet perimeter having opposite inlet portions; the first inlet passage intersects the manifold coupling passage such that one of the opposite inlet portions of the first inlet passage substantially coincides with a first manifold coupling portion of the opposite manifold coupling portions; the second inlet passage cross-section defines an outer inlet perimeter having opposite inlet portions; and the second inlet passage intersects the manifold coupling passage such that one of the opposite inlet portions of the second inlet passage substantially coincides with a second manifold coupling portion of the opposite manifold coupling portions.
 3. The manifold assembly of claim 1, wherein the first inlet axis and the second inlet axis are oriented relative to one another such that fracturing fluid flowing into the manifold passage from the first inlet passage and the second inlet passage promotes swirling of the fracturing fluid downstream of the manifold coupling.
 4. The manifold assembly of claim 1, wherein a manifold coupling cross-section of the manifold coupling perpendicular to the manifold axis at least partially defines two pairs of opposing sides, and the first inlet axis and the second inlet axis are oblique with respect to one or more of the two pairs of opposing sides.
 5. The manifold assembly of claim 1, further comprising: a first inlet manifold connected to the manifold coupling and positioned to provide a first fluid flow between the first fracturing fluid output of the first hydraulic fracturing pump and the first inlet passage; and a second inlet manifold connected to the manifold coupling and positioned to provide a second fluid flow between the second fracturing fluid output of the second hydraulic fracturing pump and the second inlet passage.
 6. The manifold assembly of claim 5, further comprising a first coupling flange connecting the first inlet manifold to the manifold coupling.
 7. The manifold assembly of claim 6, wherein the manifold coupling comprises a first coupling recess in which the first coupling flange is at least partially received.
 8. The manifold assembly of claim 7, wherein one or more of the first coupling flange or the first coupling recess has a substantially circular cross-section perpendicular to the first inlet axis.
 9. The manifold assembly of claim 7, further comprising a first coupling seal positioned to provide a fluid-tight seal between the first coupling flange and the first coupling recess.
 10. The manifold assembly of claim 6, further comprising a second coupling flange connecting the second inlet manifold to the manifold coupling.
 11. The manifold assembly of claim 10, wherein the manifold coupling comprises a second coupling recess in which the second coupling flange is at least partially received.
 12. The manifold assembly of claim 11, wherein one or more of the second coupling flange or the second coupling recess has a substantially circular cross-section perpendicular to the second inlet axis.
 13. The manifold assembly of claim 11, further comprising a second coupling seal positioned to provide a fluid-tight seal between the second coupling flange and the second coupling recess.
 14. The manifold assembly of claim 1, wherein the manifold passage has a substantially circular cross-section perpendicular to the manifold axis.
 15. The manifold assembly of claim 1, wherein one or more of: the first inlet passage cross-section is substantially circular perpendicular to the first inlet axis; or the second inlet passage cross-section is substantially circular perpendicular to the second inlet axis.
 16. The manifold assembly of claim 1, wherein the manifold coupling comprises three pairs of opposing sides substantially forming a rectangular prism, the three pairs of opposing sides comprising: a first pair of opposing sides through which the manifold coupling passage passes; and a second pair of opposing sides substantially perpendicular relative to the first pair of opposing sides, the first inlet passage extending from a first one of the second pair of opposing sides to the manifold coupling passage and the second inlet passage extending from a second one of the second pair of opposing sides to the manifold coupling passage.
 17. A manifold coupling to enhance fluid delivery to a subsurface formation, the manifold coupling comprising: a manifold coupling passage having a coupling passage cross-section defining one or more of a coupling passage shape or a coupling passage size, the manifold coupling passage having a manifold coupling axis; a first inlet passage positioned to provide fluid flow between a first fracturing fluid output of a first hydraulic fracturing pump and the manifold coupling passage, the first inlet passage having a first inlet passage cross-section at least partially defining a first inlet axis extending transverse relative to the manifold coupling axis; and a second inlet passage positioned opposite the first inlet passage to provide fluid flow between a second fracturing fluid output of a second hydraulic fracturing pump and the manifold coupling passage, the second inlet passage having a second inlet passage cross-section at least partially defining a second inlet axis extending transverse relative to the manifold coupling axis, the first inlet axis and the second inlet axis lie in a plane perpendicular to the manifold coupling axis.
 18. The manifold coupling of claim 17, wherein: the coupling passage cross-section defines an outer manifold coupling perimeter having opposite manifold coupling portions; the first inlet passage cross-section defines an outer inlet perimeter having opposite inlet portions; the first inlet passage intersects the manifold coupling passage such that one of the opposite inlet portions of the first inlet passage substantially coincides with a first manifold coupling portion of the opposite manifold coupling portions; the second inlet passage cross-section defines an outer inlet perimeter having opposite inlet portions; and the second inlet passage intersects the manifold coupling passage such that one of the opposite inlet portions of the second inlet passage substantially coincides with a second manifold coupling portion of the opposite manifold coupling portions.
 19. The manifold coupling of claim 17, wherein the first inlet axis and the second inlet axis lie in a common plane but are not parallel relative to one another.
 20. The manifold coupling of claim 17, wherein the first inlet axis and the second inlet axis are skew relative to one another.
 21. The manifold coupling of claim 17, wherein the first inlet axis and the second inlet axis are oriented relative to one another such that fracturing fluid flowing into the manifold coupling passage from the first inlet passage and the second inlet passage promotes swirling of the fracturing fluid downstream of the manifold coupling.
 22. The manifold coupling of claim 17, wherein a manifold coupling cross-section of the manifold coupling at least partially defines two pairs of opposing sides, and the first inlet axis and the second inlet axis are oblique with respect to one or more of the two pairs of opposing sides.
 23. The manifold coupling of claim 17, wherein the manifold coupling comprises: a first coupling recess configured to at least partially receive a first coupling flange; and a second coupling recess configured to at least partially receive a second coupling flange.
 24. The manifold coupling of claim 17, wherein the manifold coupling comprises three pairs of opposing sides substantially forming a rectangular prism, the three pairs of opposing sides comprising: a first pair of opposing sides through which the manifold coupling passage passes; and a second pair of opposing sides substantially perpendicular relative to the first pair of opposing sides, the first inlet passage extending from a first one of the second pair of opposing sides to the manifold coupling passage and the second inlet passage extending from a second one of the second pair of opposing sides to the manifold coupling passage.
 25. A manifold coupling to enhance fluid delivery to a subsurface formation, the manifold coupling comprising: a manifold coupling passage having a coupling passage cross-section defining one or more of a coupling passage shape or a coupling passage size, the manifold coupling passage having a manifold coupling axis; a first inlet passage positioned to provide fluid flow between a first fracturing fluid output of a first hydraulic fracturing pump and the manifold coupling passage, the first inlet passage having a first inlet passage cross-section at least partially defining a first inlet axis extending transverse relative to the manifold coupling axis; and a second inlet passage positioned opposite the first inlet passage to provide fluid flow between a second fracturing fluid output of a second hydraulic fracturing pump and the manifold coupling passage, the second inlet passage having a second inlet passage cross-section at least partially defining a second inlet axis extending transverse relative to the manifold coupling axis, the first inlet axis and the second inlet axis being parallel and offset relative to one another.
 26. The manifold coupling of claim 25, wherein: the coupling passage cross-section defines an outer manifold coupling perimeter having opposite manifold coupling portions; the first inlet passage cross-section defines an outer inlet perimeter having opposite inlet portions; the first inlet passage intersects the manifold coupling passage such that one of the opposite inlet portions of the first inlet passage substantially coincides with a first manifold coupling portion of the opposite manifold coupling portions; the second inlet passage cross-section defines an outer inlet perimeter having opposite inlet portions; and the second inlet passage intersects the manifold coupling passage such that one of the opposite inlet portions of the second inlet passage substantially coincides with a second manifold coupling portion of the opposite manifold coupling portions.
 27. The manifold coupling of claim 25, wherein the first inlet axis and the second inlet axis are oriented relative to one another such that fracturing fluid flowing into the manifold coupling passage from the first inlet passage and the second inlet passage promotes swirling of the fracturing fluid downstream of the manifold coupling.
 28. The manifold coupling of claim 25, wherein a manifold coupling cross-section of the manifold coupling at least partially defines two pairs of opposing sides, and the first inlet axis and the second inlet axis are oblique with respect to one or more of the two pairs of opposing sides.
 29. The manifold coupling of claim 25, wherein the manifold coupling comprises: a first coupling recess configured to at least partially receive a first coupling flange; and a second coupling recess configured to at least partially receive a second coupling flange.
 30. The manifold coupling of claim 25, wherein the manifold coupling comprises three pairs of opposing sides substantially forming a rectangular prism, the three pairs of opposing sides comprising: a first pair of opposing sides through which the manifold coupling passage passes; and a second pair of opposing sides substantially perpendicular relative to the first pair of opposing sides, the first inlet passage extending from a first one of the second pair of opposing sides to the manifold coupling passage and the second inlet passage extending from a second one of the second pair of opposing sides to the manifold coupling passage. 